Quiz Discussion

Three pipes P, Q and R can separately fill a cistern in 4, 8 and 12 hours respectively. Another pipe S can empty the completely filled cistern in 10 hours. Which of the following arrangements will fill the empty cistern in less time than others?

• 1] Q alone is open
• 2] P, R and S are open
• 3] P and S are open
• 4] P, Q and S are open

Pipe A can fill a tank in 4 hours and pipe B can fill it 6 hours. If they are opened on alternate hours and if pipe A is opened first then in how many hours, the tank shall be full ?

• 1]

  hours

• 2]

  hours

• 3]

  hours

• 4]

  hours

A cistern has two taps which fill it in 12 minutes and 15 minutes respectively. There is also a waste pipe in the cistern. When all the pipes are opened, the empty cistern is full in 20 minutes. How long will the waste pipe take to empty the full cistern?

• 1]

  12 min

• 2]

  10 min

• 3]

  8 min

• 4]

  16 min

Pipes A and B can fill a tank in 5 and 6 hours respectively. Pipe C can empty it in 12 hours. If all the three pipes are opened together, then the tank will be filled in:

• 1]

  hours

• 2]

  hours

• 3]

  hours

• 4]

  hours

Pipe A can fill the tank in 8 hours and pipe B can fill it in 12 hours. If pipe A is opened at 7:00 AM and pipe B is opened at 9:00 AM, then at what time will the tank be full ?

• 1] 12:00 PM
• 2] 12:30 PM
• 3] 11:48 PM
• 4] 12:36 PM

A tank can be filled by pipe A in 2 hours and pipe B in 6 hours. At 10 A.M. pipe A was opened. At what time will the tank be filled if pipe B is opened at 11 A.M. ?

• 1] 12.45 A.M.
• 2] 5 P.M.
• 3] 11.45 A.M.
• 4] 12 P.M.

Two pipes A and B can fill a tank in 20 and 30 minutes respectively. If both the pipes are used together, then how long it will take to fill the tank ?

• 1]

  10 mins

• 2]

  12 mins

• 3]

  15 mins

• 4]

  20 mins

A tap can fill a tank in 6 hours. After half the tank is filled, three more similar taps are opened. What is the total time taken to fill the tank completely?

• 1] 3 hrs 15 min
• 2] 3 hrs 45 min
• 3] 4 hrs
• 4] 4 hrs 15 min

A swimming pool is filled by three pipes with uniform flow. The first two pipes operating simultaneously fill the pool in the same time during which the pool is filled by the third pipe alone. The second pipe fills the pool 5 hours faster than the first pipe and 4 hours slower than the third pipe. The time required by the first pipe is?

• 1] 6 hours
• 2] 10 hours
• 3] 15 hours
• 4] 30 hours

A tank is filled in 5 hours by three pipes A, B and C. The pipe C is twice as fast as B and B is twice as fast as A. How much time will pipe A alone take to fill the tank?

• 1] 20 hours
• 2] 25 hours
• 3] 35 hours
• 4] Cannot be determined
• 5] None of these